The present study was conducted to check the quality of drinking
water in Sabzazar Town, District (Lahore). Samples were collected in
sterilized falcon tubes and Multiple Tube Fermentation Test was used to
analyze them. Coliforms were absent in water samples of the tube-well
and supply-line, however, they were detected in samples from consumer
taps. The coliforms were identified as E.coli by using different
morphological and biochemical tests. For the confirmation of E.coli
selective medium EMB was also used. Presence of E.coli is an indication
of unhealthy /contaminated water supply to the locality which needs
immediate attention of the concerned authorities to overcome this
problem.

Key Words: Drinking water, Quality, Consumer, Coliform,

INTRODUCTION

Water is of great importance for every living creature and for
ecological system, human health, food production and economic
development [13]. Water is the most precious natural resource on our
planet. It is seen that chemical and physical pollution of water is not
less important but the deadly pollutants present in drinking water are
of biological origin [10]. Diarrhea illness remains a major killer in
children and it is estimated that 80% of all illness in developing
countries is related to water and sanitation; and that 15% of all child
deaths under the age of 5 years in developing countries result from
diarrhea diseases [19,20,18].

A large number of bacteria live in water because nutrients are
widely distributed in the water [14]. Water is one of the vital source
of gastrointestinal diseases. That is why water used for drinking
purpose should be free from micro-organisms and chemical substances.
Water becomes contaminated when it contains poisonous chemical
substances, industrial or sewage waste and parasitic agents [2].
Coliforms are facultative anaerobic, non-spore-forming Gram negative
bacilli that produce gas and acid by fermentation of lactose. The most
important species of this group are Eschesichia coli and
Enterobacteraerogenes. Coliform bacteria, especially, E. coli are
permanently present in human intestine in huge number. The presence of
coliform bacteria in water is indication of fecal contamination of human
and animal origin [12]. In rainy seasons, coliform bacteria are thrown
away into streams, rivers, lakes, ground water and creeks.

Drinking water from these untreated sources contains coliform
particularly E. coli. In Pakistan open sewage drains and water supply
lines run parallel resulting in continuous contamination of drinking
water [11]. E.coli is an opportunistic pathogen in newborn and
immune-deficient patients [3]. Various diseases are caused by E. coli
such as urinary tract infection, wound infection, gastrointestinal
infection and Bacteremia [15]. Epidemics of E. coli have been recorded
from many countries due to contamination of drinking water and food
[9,11].

The objective of this research work was to evaluate the drinking
water quality in Sabzazar Lahore both at the source and in distribution
system and to suggest preventive measures.

MATERIALS AND METHODS

Three sites of Sabzazar Town (Lahore) were selected for collection
of water samples i.e., Tube well, Supply line and Consumer
taps(household). Total ninety samples were collected, thirty from each
site.Samples were collected in sterilized falcon tubes.pH was also
determined during sampling, and samples were brought immediately to the
laboratory.

To check the coliform bacteria in water samples, Multiple Tube
Fermentation Test (MTFT), was performed which consists of following
three steps:Presumptive coliform test, Confirmed coliform test and
Completed coliform test.

Presumptive Coliform Test: 9 ml of MacConkey broth was added in
each test tube. A Durham tubewas placed in inverted position in each
tube.Test tubes were plugged with cotton swabs having aluminum foil and
sterilized at 121degC and 15lb pressure for 15-20 minutes in autoclave.
After sterilization, test tubes were placed in laminar air flow chamber
and allowed to cool down for few minutes. Then 1 ml of water sample was
added with the help of sterilized pipette in each test tube. After that,
test tubes were placed in incubator at 37degC for 24 hours.

Confirmed Coliform Test: Eosine methylene blue agar (EMB agar)
mediumwas used to performthis test.After sterilization, the flask
containing EMB agar medium was placed in laminar air flow cabinet and
poured the medium into sterilized petriplates.The medium was allowed to
solidify. After solidification, 10 ul of culture was taken from the test
tube showing gas bubble and spread it on Petri plates with the help of
spreader. Then Petriplateswere incubated at 37degC for 12 hours. After
incubation picked a loopful of culture from spreading plates and
streaked it on the petriplates containing EMB agar medium. After
streaking, the Petri plates were placed again in incubator at 37degC for
24 hours.

Completed Coliform Test: Completed coliform test was performed for
the final analysis of water samples. Took a loopful of culture from the
EMB agar streaking petriplates and inoculated it into 9 ml of sterilized
MacConkey broth in test tubes containing inverted Durham tubes. Then
incubated the test tubes at 37degC for 24 hours.

Water samples collected from three sites of Sabzazar, District
Lahore were examined for coliform detection. pH of water samples ranged
between 7 to 7.5. No coliform were found in water samples taken from
tube well and supply line, because,in presumptive test, no acid and gas
production or color change occurred and no metallic sheen colonies were
seen in confirmed test. In completed test also no acid and gas
production was observed which means water samples from these two sources
were free from contamination so water of these sources is suitable for
drinking. However, water samples taken from consumer's taps were
found to be contaminated with fecal coliforms. Since there was acid and
gas production and change in colour from blue to yellow. Metallic sheen
was also noticed on petriplates which confirmed the presence of
ColiformIn confirmed test presence of metallic sheen indicated the
presence of E.coli. It means water is not fit for drinking purpose
(Figs. 1 to 4).

Gram staining and endospore staining were performed which indicated
that they were negative, non-spore forming rods. Different biochemical
tests were performed for the confirmation of E.coli. All strains showed
positive results for indole and methyle red tests (Fig., 5-6) and
negative results for citrate and vogesproskauer tests, which confirmed
the presence of E.coli.

DISCUSSION

The government of many countries has always been trying to
determine the quality of water for purposes of domestic consumption,
drinking, some medical situation and personal hygiene. World Health
Organization (WHO) provided criteria to improve and check the quality of
drinking water in Pakistan against these standards [17].

In present study, to determine the quality of drinking water in
Sabzazar Lahore Multiple Tube Fermentation Test (MTFT) was used. MTFT is
a standard method which has been used for about 80 years to check the
quality of drinking water [16]. In Sabzazar town water quality was
determined at three sources i.e. tube well, supply line and consumers
taps. From the first source (tube well) no coliform bacteria were found
that is why it is potable water. No coliform bacteria were detected in
second source (supply line). But in third source coliform (E.coli) were
present, it means water is non-potable; it indicates the mixing of
sewage water at consumer level. Now-a-days, bacteriological
contamination of drinking water is a big issue.

At consumer level the drinking water is becoming more polluted due
to unhygienic handling and open storage tanks. In the rural areas of
Rawalpindi 73-90% water samples were found contaminated with coliform
and non-coliform bacteria [6]. Our results relates with the study
conducted by [8] in which water samples collected from source and supply
line were free from coliform.

According to estimation about 1.5 billion people lack clean
drinking water and 5 million deaths per year can be occurred due to
water borne diseases [1]. For the supply of safe drinking water for
human use regular chlorination should be done and homes filter should be
used. Suitable monitoring system should be adopted to decline the
contamination of water. In Sabzazar water quality status is low and
therefore water borne diseases are common in children. It has been
determined that water quality changes during distribution system from
source to consumers. In future, plans must be prepared to supply safe
drinking water to the residents.